In a cellular communication system, a large geographic area is divided into multiple cells. Physical resources—such as frequency channels, spreading codes, timeslots etc.—are re-used from cell-to-cell to maximize system capacity. Within a cell, a single base station communicates with a subset of the mobiles. These mobiles are assigned to cells by handoff algorithms that direct the mobile to the most appropriate cell. Once a cell has been selected, communications are generally considered to be confined within the cells boundaries and protocols are defined for point-to-multi-point communication between one base and the sub-set of mobiles.
Practically, radio communications are not confined by the cells geographic boundaries and cross-cell communication occurs where a base station may communicate with mobiles in adjacent (or more distance) cells. Cross-cell communication can be problematic for a number of reasons:                Cell Selection—a mobile must select the most appropriate cell and then retain connection to that cell. Therefore a mobile must be able to distinguish between signals received from multiple cells and uniquely identify the most appropriate cell.        Association—once selecting an appropriate cell the mobile must clearly associate itself with that cell. As a result, the mobile must transmit a signal that allows a base station receiving these signals to differentiate between a signal that is intended for it or another base station.        Protocol Consistency—as stated protocols are defined for a single base station and a sub-set of mobiles. Cross-cell communication can often intermingle the transmissions of several mobiles, associated with different cells, resulting in a protocol error. For example, the address space used to communicate with the sub-set of mobiles is re-used for cell-to-cell. Therefore, directives intended for one mobile may be interpreted by another mobile in an adjacent cell.        
To overcome the problems of cross-cell communication, many methods are used to distinguish cell sites. For some systems, geographic frequency re-use is partitioned in such a way that geographically close cells do not use the same frequency alleviating much of the cross-cell communication problems. For systems employing a large frequency re-use pattern, simple means are appropriate to distinguishing between cells such as a transmission of a cell-specific reference signal (e.g., base station ID field). However, for more aggressive re-use patterns cross-cell communications must employ alternate techniques to identify base stations and mobiles. Therefore a need exists for a method and apparatus for choosing reference signals to be transmitted in a communication system that employs a more-aggressive frequency re-use pattern.